The theater chain is citing security reasons for the new rule.

In an effort to enhance the safety and moviegoers, Cinemark theaters are now banning large bags. Any bags or packages that measure larger than 12 inches by 12 inches by 6 inches will no longer be allowed inside a Cinemark theater, with the exception of medical and diaper bags.

Cinemark—which operates more than 500 theaters worldwide under the names Century Theatres, Tinseltown USA, CineArts and Rave Cinemas—does not provide an area to check bags or belongings that aren’t allowed. And they say all bags, regardless of size, will be subject to search. So it’s best to just not bring any bags you don’t need.

This change comes as people continue to worry about gun violence across the United States. And although it’s been almost six years since 12 people were killed at a Cinemark-owned theater in Aurora, Colorado, that memory is still fresh in the minds of many. Some victims of the Aurora shooting filed a lawsuit against Cinemark saying security flaws led to the attack.

This new policy is not surprising considering current security issues and worries, nor is it unlike other policies already in place at other top theater chains, as well as at sports stadiums and concert venues.

Regal Cinemas, which also operates more than 500 theaters in the United States, says all backpacks, packages and large bags are subject to inspection. You are also not allowed to wear costumes with masks, face paint or any other item that obscures your face and, of course, cannot posses weapons or prop weapons. AMC Theatres—the nation’s biggest chain—has a similar policy regarding costumes and weapons.

When it comes to larger venues, if you plan on going to any NFL games, make sure any bags you want to take into the stadium are clear. Aside from medical bags, the only other bags allowed must be clear plastic, vinyl or PVC and, similar to Cinemark’s new rules, must not be bigger than 12 inches by 12 inches by 6 inches.

The same goes for multiple sporting venues and concert arenas around the country, so be sure to check individual bag policies before attending an event.